1. Field of the Invention
The present invention relates to an electromagnetic clutch for a manual transmission, in which the engine power is temporarily interrupted during the course of speed change through the transmission when the engine power is transmitted to the driving wheel through the clutch and the transmission. More specifically, the invention relates to an electromagnetic clutch for a manual transmission, in which the structure thereof is improved in order to more certainly transmit the power, the impact caused by the speed change can be minimized, thereby improving the service lifespan thereof, along with the economical efficiency and safety.
2. Background of the Related Art
In the conventional manual transmission mode, the speed change is carried out by operating a gear lever with the clutch pedal stepped on. Therefore, a driver suffers from an inconvenience of having to continuously and manually perform the speed change depending on the speed, when traveling.
Accordingly, in order to promote the convenience for drivers, various automatic transmission techniques have been recently developed, in which the speed change of the car is automatically carried out by a mechanism. However, it cannot be a complete solution therefor, in terms of the advantages of the vehicle adopting the conventional manual transmission, such as the cost, the weight, the rate of fuel consumption and the acceleration performance.
As one approach in order to solve the above problems, Japanese patent Laid-open Publication No. Pyung16-232835 discloses an automatic clutch, in which an electromagnetic 59 is adopted, while using the conventional manual transmission mode. As shown in FIG. 1, the above automatic clutch 1 includes an electromagnet 59 fixedly attached thereto, an armature 61 corresponding to the electromagnet 61, a friction clutch 63 integrally formed with the armature, which moves by the magnetic force of the electromagnet.
The convention technique having the above-described construction is configured in such a manner that the armature is drawn by the magnetic force of the electromagnet, plural friction clutches are contacted with one another and rotated by the movement of the armature, thereby selectively transmitting the engine power to the transmission.
However, the above-mentioned conventional electromagnetic clutch device embraces several problems. For example, the contact and rotation of the friction clutch relies on the frictional force by the magnetic force of the electromagnet only, so that the power transmission cannot be adequately performed. Therefore, at the time point of starting or speed-changing, the impact caused by the speed change is overly generated, thereby inducing discomfort to the driver, along with the excessive fuel consumption and the complexity of structure therefore.